Polishing wheel and cement therefor



COltlPOSlTIONS, m COALING Oi?i ELASTIC atente ct. 8, 1946 Examleer CROSStime ,smrs mm T Omar;

, POLISHING WHEEL AND CEMENT.

THEREFOR HaroldR. Nelson, Detroit, Mich.

No Drawing. Application July 17, 1944',

Serial No. 545,399

The present invention pertains to a novel polishing wheel and cementtherefor. Polishing or buiilng wheels composed of a body of vegetable oranimal fibrous material, such as felt, cotton, leather or sheepskin, areknown in the art. It is also customary to secure abrasive grains to thesurface of such a wheel by means of an adhesive.

One of the difliculties encountered in the use of such a wheel issoftening of the adhesive by the heat developed in use, with the resultthat the abrasive coating deteriorates. More specifically, the abrasivegrains become buried in the adhesive or, in other words, the workingsurface becomes glazed and hence worthless for its intended p pose.

The principal object of the invention is to over-- come this diificultyand thereby prolong the useful life of the wheel. This object isaccomplished by the use of an adhesive that is substantially moreresistant to heat than adhesives previously used in this art.

Inasmuch as other cements become brittle when their heat resistance isincreased by modification of the ingredients, and brittleness is highlyundesirable in a polishing wheel, another object of the invention is toprovide a cement that has high resistance to heat without sacrificingits pliability. This desirable combination of properties is broughtabout by a particular selection of ingredients as hereinafter set forth.

The novel adhesive is characterized by the use of a relatively smallamount of finely ground asbestos incorporated in a combination of claysand other materials.

V A typical and satisfactory adhesive is composed as follows:

Claims (01. 51-30 insofar as the invention is concerned, is the silicaand alumina content.

In relation to the aforementioned ingredients, the asbestos varies from2.5% to about 6%. Water may be added until the desired consistency orthe purpos at hand is obtained. Likewise, the clay or a mixture ofdifferent clays may be selected for special requirements, although thosementioned above are generally satisfactory.

In preparing the composition, the ingredients are charged into a vesseland heated, with stirring, until a uniform consistency has beenproduced.

In coating the wheel, the surface of the body to be employed forpolishing or buffing is first coated with the adhesive. The adhesivegrains are then applied either by sprinkling, laying the coated surfaceagainst a mass of abrasive grains or, if the periphery is to be treated,rolling the wheel over a mass of grains. After the adhesive has dried,the wheel is ready for use.

A wheel made up in this manner has a considerably longer life than priorwheels having abrasive grains cemented to a fibrous body. In fact, sucha wheel can be subjected to a pressure enabling it to cut through athickness of Parts by weight Silicate of soda 834 chippmg- Hanover clay26 40 The invention is not limited to the foregoing Brunswick clay 26formula which has been given only as an il- Other clay 3 lustration.Various modifications are feasible in Aluminum silicate 0 the selectionof grades of material and the ad- F nely ground asbestos 25 t 0 ditionof special ingredients with regard to specific requirements. Theinvention is character- The chemical composition of Hanover clay andBrunswick clay is as follows:

ized by the presence of a relatively small quantity of asbestos and inother respects as indicated by the appended claims.

' It will also be understood that the invention iii flitiiy is notrestricted to the precise materials disclosed MW) herein and that theappended claims are intended Percent Per cent to embody the legal rangeof equivalents. 333 Having thus fully described my invention, what g Iclaim and secure by Letters Patent is: 110 1110 1. A polishing membercomprising a fibrous I body, abrasive particles adhered thereto, the ad-01'7 0109 hesive for said particles containing 2 to 6% 13-75 of finelyground asbestos and about 10% of clay The important in relation to thesolid content.

2. A polishing member comprising a fibrous body, abrasive particlesadhered thereto, the admately, by weight, 850 parts of silicates, themajor portion of which is sodium silicate, 26 parts Hanover clay,'26parts Brunswick clay, 48 parts of other clay, and 25 to 60 parts offinely ground asbestos fiber.

5. A polishing member comprising a fibrous body, abrasive particlesadhered thereto, the adhesive for said particles containingapproximately, by weight, 834 parts of sodium silicate, parts ofaluminum silicate, 100 parts of clay, and to parts of finely groundasbestos fiber, 26 parts Hanover clay, 26 parts Brunswick clay, 48 partsother clay, and 25 to 60 parts of finely ground asbestos fiber.

HAROLD R. NELSON.

